Lithium batteries can be divided into cylindrical batteries, square batteries, and soft pack batteries according to their packaging methods. Although square batteries are the mainstream power batteries in the current market, each of the three types of batteries has its own advantages and disadvantages. In terms of cylindrical batteries, Tesla is particularly impressive in the field of power batteries. From 18650 to 21700, and to the upcoming mass production of 46800 batteries, Tesla is basically leading the trend.

Taking the 18650 battery as an example, 18 represents the diameter of the battery, 65 represents the height of the battery, and 0 represents that it is a cylindrical battery. Therefore, 27100 and 46800 are naturally the same. The 18650 battery was the earliest lithium battery packaging method developed, and by 1992, cylindrical batteries had already been widely developed. Initially, the majority of 18650 batteries were used in digital products.

Due to its first mover advantage, cylindrical batteries are the most technologically mature packaging method. Specifically, 18650 has a higher yield rate and the cost of PACK can also be effectively controlled. Compared to square hard shell batteries, cylindrical batteries have insufficient space utilization, but they can use the gap in the center of the cylinder to circulate coolant, which is also considered a type of space utilization.

In terms of defects, the disadvantage of 18650 cannot be ignored. Firstly, the 18650 battery adopts a metal shell and has a smaller capacity as a single battery. In order to meet the capacity demand, it can only be compensated by a significant increase in quantity. Therefore, a larger quantity requires higher requirements for the BMS battery management system.

The square battery is currently the most widely used battery in the lithium battery category. A series of mainstream new energy vehicle companies in China, such as BYD, Geely, and NIO, all use square hard shell batteries, while traditional international manufacturers such as Audi and BMW also use square battery solutions. One of the most important reasons for the wide use of square batteries is that they have more suppliers and relatively low technical difficulty. The vast majority of domestic battery suppliers choose to develop square batteries. For example, well-known suppliers such as Ningde Times, BYD, and Guoxuan High Tech are important suppliers of square hard shell batteries.

In addition to its abundant suppliers, it also has a higher degree of customization and a higher utilization rate of square space compared to cylindrical batteries. However, the problem is that the hard maintenance shell on the outer layer will significantly increase the overall weight of the battery pack. Therefore, similar ideal ONEs in China have begun to use aluminum as the outer maintenance shell, effectively ensuring lightweight and improving battery energy density.

Along with this, the individual capacity and volume of square batteries are larger, and the number of individual cells naturally decreases, resulting in lower requirements for the BMS battery management system. The most representative square hard shell motor now is the NCM811 battery launched by the Ningde era.

The downside of square batteries lies in their high customizable freedom, which leads to inconsistent manufacturing processes and highlights the differences between each battery. Compared to cylindrical batteries, square hard shell batteries have higher requirements for cooling system placement. However, with the introduction of national battery regulation policies, the differences in square batteries will also decrease in the future.

Although soft pack batteries are increasingly being used in the sedan market, we are not unfamiliar with them due to the fact that lithium batteries in mobile phones are mostly packaged as soft pack batteries.

The shell of the soft pack battery is made of aluminum plastic film material, which is lighter in weight compared to square and cylindrical batteries made of aluminum shell. Under equal capacity, the weight of a soft pack battery is 20% lighter, while under equal capacity, the capacity of a soft pack battery is 50% higher than that of an aluminum shell battery.

So the theoretical energy density of soft pack batteries is higher than that of square and cylindrical batteries. In terms of defects, soft pack batteries now need to address issues such as standardization and high cost, heavy reliance on imports for high-end aluminum plastic films, and poor consistency.

Shenzhen Topband Battery Co., Ltd.，established in 2006, is a wholly-owned subsidiary of Shenzhen Topband Co., Ltd. (002139.SZ). We focus on lithium iron phosphate batteries,with independent research and development in cells and BMS. With the ability to integrate the entire industry chain, we are committed to providing customers with one-stop lithium battery solutions and services. Our quality products are widely used in energy storage and light power.